xStarter can listen to the TCP/IP ports you specify. No sniffing, it just waits for commands or data from other computers. It is also possible to send commands.

For example, you can use these features to send commands to all computers on the local area network in order to launch tasks checking if there is 1C running. Computers where 1C is running will return "Running", while other computers will return "Not running". Computers that will not return anything are either off or blocked by a firewall. You will have to check them manually.

But actually the attached example is not quite on this topic, it just shows basic operations of receiving and sending commands via TCP/IP.